Executing sendmail_test itself works fine, only when used for sendmail_path it fails.

The workaround for me is to use "#!/usr/bin/php -n" for this script (-n for "no ini and therefore also no xcache).Debian/Ubuntu? uses the same conf.d directories for CLI and CGI, otherwise I might have disabled XCache for CLI instead.

If you need more information, like e.g. a backtrace in case you cannot reproduce this, please let me know.

btw, the reason it "out of memory" in this specified case, is because when the parent (the var_dump one) is executed, shared memory is allocated for this process, and when sendmail_path is executed as another process, one more shm is allocated which might have exceeded the limitation.